The present patent application document is somewhat related to the copending and commonly assigned patent application document "MICRO CHANNEL HEAT PIPE HAVING WIRE CLOTH WICK AND METHOD OF FABRICATION", AFD 00344, Ser. No. 09/389,269 filed on even date herewith. The contents of that even filing date application are hereby incorporated by reference herein.
The present invention relates generally to heat dissipating devices and more particularly to a micro channel heat pipe and method of fabrication.
As is well known in the art, heat pipes are closed, self contained devices that contain a volatile working fluid designed to transport thermal energy efficiently. In general, heat pipes have an inner cavity lined with a wick or grooves designed to provide a capillary structure for the transport of the working fluid.
In operation, the heat pipe takes advantage of the latent heat of vaporization of the working fluid. Heat is applied to one portion of the device, causing evaporation of the fluid in that portion of the chamber. The fluid vapor moves to a cooler portion of the device whereupon it condenses. The condensed fluid returns, and the action repeats itself.
As can be imagined, this vaporization and condensation action is continuous and provides for a very efficient means of transportation of thermal energy. The heat pipe is a sealed unit and requires no additional energy input to enable operation. Thus it is very efficient and is useful in a wide array of applications.
A current trend towards micro miniaturization of electronic components and high power devices gives rise to the desirability of correspondingly miniaturized cooling devices. As a result, attempts have been made to miniaturize heat pipes. However, as heat pipes are miniaturized, it becomes increasingly difficult to fabricate an effective capillary channel structure to provide acceptable heat transfer operation. For example, forming of very narrow rectangular channels, 0.2 mm.times.0.9 mm or similar sizes and shapes within the internal walls of tubes with hydraulic diameter in the range of 5-10 mm is difficult. Appropriate groove cutting tools, extrusion dies and the like, necessary for cutting such small channels often provide unsatisfactory results and are expensive.
A need exists therefore for a micro channel heat pipe which provides high efficiency operation while simultaneously eliminating the difficulties encountered in fabrication heretofore encountered to date.